Unit1 test Questions

p Don't forget multiple choice style! And the word "describe" is a question type I almost never use! Copy my style! ~Leslie

If each person posts one questions for chemistry we can easily make 25..assuring that we know 5 of the questions on the test on monday!

Manuel: Describe Metallic Bonding, Electron Delocalization and its' effects on the structure of metally bonded elements.​ (yo Manuel, this question is too hard, make it a multiple choice or something. Besides, look at what Leslie said.-Conrad) Actually I think the part of the question that says "describe its effect etc..." is perfectly fine. ~Leslie

​ Answer: Metallic bonding occurs when the valence orbitals overlap and electrons become delocalized. The electrons now belong to a shared area, created by this bond. Metalluic bonds have high conductivity because the extra space for electrons allows for more activity. As well, metals usually bend not break, this is because the electrons have lots of room to rearrange themselves in. The reason metals are solids at room temperature is because of the abindance of these valence shell electrons.

(um I think the questions have to be multiple choice and i think it would be good if we put at least the correct answer to them. We could even make the false ones to make everyone elses' lives easier.)
​
1. Which one of these is not an intermolecular force? - Manuel
a) covalent bonding <---Correct Answer
b) hydrogen bonding
c) dipole-dipole forces
d) london dispersion forces
e) none of the above

2. Which element has the highest atomic radius?-Vlad
a) Francium (Fr) <---Correct Answer
b) Astatine (At)
c) Radon (Rn)
d) Polonium (Po)
e) Hydrogen (H)

3. In the alcohol C2H6O, what are the hybridizations of each element? - Isabel
a) Hydrogen = no hybridization, Carbon = sp3, Oxygen = sp <--- I'm pretty sure this is the correct answer, please clarify someone (scott). Scott, you have to take into consideration the two lone electron pairs on the oxygen (Isabel)
b) Hydrogen = sp, Carbon = sp3, Oxygen = sp3
c) Hydrogen = no hybridization, Carbon = sp3, Oxygen = sp3 <--- Correct Answer
d) Hydrogen = no hybridization, Carbon = sp2, Oxygen = sp3
e) Hydrogen = sp, Carbon = sp3, Oxygen = sp2



4. Which is NOT true for Ionization Energy? - Danielle
a) Ioniztion energy is the energy needed to remove an electron from a neutral atom
b) Ionization energy increases when moving right on the periodic table
c) Ioniztion energy is the energy released when adding an electron to an atom <--- Correct Answer
d) Ionization energy increases when moving up on the periodic table

5.What is the electron configuration of Arsenic? - David
a) [Ar] 4s2 4d10 4p3
b) [Ar] 4s2 3d10 4p3 <--- Correct Answer
c) [Ar] 4p3
d) [Kr] 4s2 3d10 4p3
e) [Kr] 4s2 4d10 4p3

6.Pi bonds result from: -Simone
a) direct overlapping of orbitals
b) parallel overlapping of orbitals <---- Correct Answer
c) when the bonds make a pi shape
d) none of the above

7.In tin (Sn), which of the following orbitals is loaded first? - Deanna
a) 5s <----- Correct Answer
b) 4d
c) 5p
d) 4f
e) 5d

8.Which of the following will NOT have an electron configuration ending with 3s2 3p6? -Tiana # 8-16
a) chloride ion
b) sulfide ion
c) aluminum ion <- correct answer
d) calcuim ion
e) potassium ion

9. Which of the following bonds is most polar?
a) N-O
b) C-H
c) O-H <- correct answer
d) H-Cl
e) C-Cl

10. A Lewis symbol for an atom with a configuration of 1s2 2s2 2p3 would show:
a) 1 unpaired electron and 3 electron pairs
b) 2 unpaired electrons and 2 electron pairs
c) 1 unpaired electron and 2 electron pairs
d) 3 unpaired electrons and 1 electron pair <- correct answer
e) 3 unpaired electrons and 2 electron pairs

11. A molecule of a substance with physical properties primarily determined by London forces would be:
a) SiC
b) KCl
c) Na3P
d) PCl3 <- correct answer
e) H2O2

Can someone please explain this? I know we can eliminate b and c because that's ionic and e is H-bonds, but how do you decide between a and d?
-Simone
Hmm... are you sure the correct answer is PCl3? PCl3 has a lone pair and 3 single bonds, which means it's polar isn't it? Also, Si and C have different electronegativity values, meaning they would be polar too????? In that case, both of them wouldn't be right (dipole forces instead)????? -- Andy
Well, i dont think they're dipole forces because the difference in electronegativity between the atoms is less than 1.7. I got this question from the textbook and i just realized how hard it is.... The only way i can see PCl3 as the right answer is because Cl has a higher electronegativity than P... Which means that there is a slightly negative charge around the entire molecule (taking into account the lone pairs too) ... so london dispersion occurs - Tiana
For SiC, a molecule doesn't have to be polar covalently bonded to have poles right? (or does it?)
PCl3 is weird, are we expected to know that 3 chlorine atoms' charge cancels that of the lone pair?

SiC prob has covalent bonds. PCl3 is non polar because of its symmetry, it actually has 2 pairs of lone electrons (trigonal bi-pyramidal shape). Sry it's late, but I ve been terribly sick and busy this weekend. - Qing


12. The biggest flaw in Bohr`s theory was that it:
a) did not apply to atoms larger than hydrogen <- correct answer
b) predicted electrons would slow and spiral into the nucleus
c) did not explain blackbody radiation
d) predicted that protons in the nuclei would repel and fly apart
e) ignore the structure of the nucleus

13. A Lewis structure for the hydroxide ion OH- , would show
a) 3 electron pairs
b) 4 electron pairs <-- correct answer
c) 7 electron pairs
d) 10 electron pairs
e) 12 electron pairs

Does a bond count as an electron pair?????????
Yes



14. An energy level diagram for fluorine would show the highest level of energy for:
a) 7 electrons <-- correct answer
b) 9 electrons
c) 10 electrons
d) 18 electrons
e) 19 electrons

15. The evidence that all substances are attracted or repelled by a magnetic field is described by the:
a) principal quantum number, n
b) secondary quantum number, l
c) magnetic quantum number, ml
d) spin quantum number, ms <- correct answer
e) electron configuration

16. The atoms of hard, brittle substances with high melting points are essentially all joined in a network of:
a) ceramic bonds
b) coordinate bonds
c) metallic bonds
d) covalent bonds <-- correct answer
e) hydrogen bonds

17. The major differences on electron energy levels are described by the: - Alissa :)
a) principal quantum number , n <-- correct answer
b) secondary quantum number, l
c) magnetic quantum number, ml
d) spin quantum number, ms
e) exclusion principle

18. The idea of special stability due to the presence of a stable octet of electrons is central to: -Tiana # 18-20
a) Kekule line diagrams
b) Bohr atomic structure
c) VSEPR molecular shape prediction
d) Pauling hybrid orbitals
e) Lewis dot diagrams <- correct answer

19. The molecule in the following list that has a linear shape, according to VSEPR theory, is:
a) H20
b) OF2
c) CO2 <- correct answer
d) H2O2
e) CH3COOH

20. A Lewis symbol for a negative ion with a configuration of 1s2 2s2 2p6 would show:
a) 3 unpaired electrons and 2 electron pairs
b) 1 unpaired electron and 3 electron pairs
c) 2 unpaired electrons and 3 electron pairs
d) no electrons, either single or paired
e) 4 electron pairs <-- correct answer

21. How many sigma and pi bonds are there in a triple bond?- Vlad (21-25)
a) 3 sigma bonds
b) 3 pi bonds
c) 1 sigma bond and 2 pi bonds <--- Correct Answer
d) 1 pi bond and 2 sigma bonds
e) 1pi bond and 1 sigma bond

22. If you have 1s and 3p orbitals go into hybridization, what type of orbitals come out? Can someone explain why the answer would be 'c'? I thought it would be 'a' b/c you have 4 orbitals entering hybridization which means 4 orbitals would result..... Tiana
Can you actually answer this question because you don't know the situation in which you need those orbitals for????-Simone
Yeah I messed up the answer would be a) 4sp hybridized orbitals because of Tiana's reasoning and I'm pretty sure you can answer this question as it meantions that those orbitals go into hybridization for sure.

a) 4 sp hybridized orbitals <---Correct Answer
b) 1s and 3p orbitals
c) 3 sp hybridized orbitals
d) 5 sp hybridized orbitals
e) 1 sp hybridized orbital

23. What is the strongest intermolecular force?
a) Dipole-dipole
b) London Forces
c) Hydrogen Bonds <---Correct Answer
d) Ionic Bond
e) none of the above

24. How many lone pairs does hydrochloric acid (HCl) have?
a)1
b)2
c)3 <---Correct Answer
d)4
e)5

25.What molecule has the electron configuration [Ar] 4s2 3d3?
a) Arsenic
b) Vanadium <---Correct Answer
c) Niobium
d) Arsenic
e) Plutonium

26. Hydrogen Bonding helps us explain
a) surface tension <--correct answer
b) the flexibility of metallic materials
c) the toxicity of methane
d) dipole dipole forces
e)ionization energy